Protect PDF
Lock a PDF with real encryption, so it simply cannot be opened without your password. Everything happens in your browser — the file and the password never leave your device.
You can also restrict printing, copying, and editing. Those restrictions are a request to the PDF reader rather than something encryption enforces — a password is the part with real strength behind it.
How to password protect a PDF
- Open your PDF. Drag the file onto the drop zone, or click it to browse.
- Set a password. Enter the password needed to open the document, and optionally restrict printing, copying, or editing.
- Encrypt and download. Click Protect PDF and download the encrypted copy. Keep the original safe — a forgotten password cannot be recovered.
Frequently asked questions
What happens if I forget the password?
The document cannot be opened again. That is not a limitation of this tool — it is what encryption means. Nobody, including us, can recover it, so keep the original file somewhere safe before you protect a copy.
What's the difference between a password and the restrictions?
A password encrypts the contents, so the document cannot be read without it. The restrictions — printing, copying, editing, comments — do not encrypt anything; they ask the PDF reader to disable those actions. Most readers honour them, but some ignore them, so treat restrictions as a deterrent rather than a guarantee. A password is the part with real strength behind it.
Is my PDF or password uploaded anywhere?
No. Both stay on your device. The encryption runs in your browser, so neither the file nor the password you choose is ever sent to a server.
Can I change the password on a PDF that already has one?
Yes. Choose the file, enter its current password when asked, then set the new one. The old password stops working on the copy you download.
Will bookmarks, links, and form fields survive?
Yes. Applying protection rebuilds the document, so bookmarks, form fields, named destinations, and the accessibility structure are copied across deliberately rather than left behind.
How strong is the encryption?
The PDF standard security handler is used, which is what every PDF reader supports natively — no special software is needed to open the result. As with any password-based encryption, the real strength comes from the password: a short one can be attacked offline no matter how good the cipher is, so a passphrase of several words is worth far more than a short complex one.